道路钢护栏用Q345钢焊接接头的耐蚀性能研究

Corrosion Resistance of Welded Joints of Q345 Steel Used for Road Steel Guardrail

研究了手工电弧焊（SMAW）、钨极氩弧焊（TIG）和CO2气体保护焊（GMAW）对Q345钢焊缝和热影响区在不同温度3.5%NaCl溶液中腐蚀行为的影响。结果表明,当腐蚀介质温度从20℃上升至40℃时,Q345钢母材、SMAW焊缝和热影响区、TIG焊缝和热影响区、GMAW焊缝和热影响区的腐蚀电流密度都呈现逐渐升高的趋势,腐蚀速率增大;当腐蚀介质温度从40℃上升至60℃时,Q345钢母材、SMAW焊缝和热影响区、TIG焊缝和热影响区、GMAW焊缝和热影响区的腐蚀电流密度都随着腐蚀介质温度升高而降低,腐蚀速率减小。当腐蚀介质温度为20℃和40℃时GMAW焊缝的腐蚀速率最小,60℃时TIG焊缝的腐蚀速率是三种焊缝中最小的;当腐蚀介质温度在20-60℃时,热影响区的腐蚀速率都高于Q345钢母材,且3种焊缝中CO2气体保护焊热影响区的腐蚀速率最小。

The effects of manual arc welding（SMAW）,tungsten arc welding（TIG）and CO2gas shielded welding（GMAW）on the corrosion behavior of the weld zone and heat affected zone of Q345 steel in the 3.5%NaCl solution at different temperatures were studied.The results show that the corrosion current density of Q345 steel base material,SMAW weld and heat affected zone,TIG weld and heat affected zone,GMAW weld and heat affected zone increase gradually when the corrosion medium temperature rises from 20℃to 40℃,and the corrosion rate increases.When the corrosion medium temperature rises from 40℃to 60℃,the corrosion current density of Q345 steel,SMAW weld and heat affected zone,TIG weld and heat affected zone,GMAW weld and heat affected zone all decrease with the increase of corrosion medium temperature,and the corrosion rate decreases.When the corrosion medium temperature is 20℃and 40℃,the corrosion rate of GMAW welds is the smallest,and the corrosion rate of tungsten TIG welds is the smallest in the three kinds of welds when the corrosion medium temperature is 60℃.When the corrosion medium temperature is 20-60℃,the corrosion rate of the heat affected zone is higher than that of the Q345 steel,and the corrosion rate of the heat affected zone of the CO2gas protection welding of the 3 kinds of welds is the smallest.